// SPDX-License-Identifier: MIT
//
// Linux system call names and numbers.
// Copyright (c) 2021  William Findlay
//
// June 14, 2021  William Findlay  Created this.

//! Get system call information for the Linux kernel according to your target
//! architecture.

#![crate_name = "sysnames"]
// Only supported on Linux (for now)
#![cfg(target_os = "linux")]
// Everything should be documented
#![deny(missing_docs)]

mod syscalls;

/// Get system call information for your target architecture.
/// Currently only supports the Linux kernel.
pub struct Syscalls;
impl Syscalls {
    /// Get a system call name by its number, if it exists on your architecture.
    ///
    /// ```rust
    /// use sysnames::Syscalls;
    ///
    /// let execve_num = Syscalls::number("execve");
    /// assert!(execve_num.is_some());
    /// ```
    pub fn number(name: &str) -> Option<u64> {
        syscalls::SYSCALL_NUMS
            .get_by_left(name.to_lowercase().as_str())
            .cloned()
    }

    /// Get a system call number by its name, if it exists on your architecture.
    ///
    /// ```rust
    /// use sysnames::Syscalls;
    ///
    /// let execve_name = Syscalls::name(59);
    /// assert!(execve_name.is_some());
    /// ```
    pub fn name<'a>(number: u64) -> Option<&'a str> {
        syscalls::SYSCALL_NUMS.get_by_right(&number).cloned()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn name_number_bijection_test() {
        let number = Syscalls::number("execve").unwrap();
        let name = Syscalls::name(number).unwrap();
        assert_eq!(name, "execve");
    }

    #[test]
    #[cfg(target_arch = "x86_64")]
    fn execve_x86_64_test() {
        let name = Syscalls::name(59).unwrap();
        assert_eq!(name, "execve");

        let number = Syscalls::number("execve").unwrap();
        assert_eq!(number, 59);
    }
}